To pronounce "föhn" properly, you've got to make the shape of "o" with your mouth, but say "ee" through it. That's an umlaut-o, also spelled "oe". And it does have the whisper of an "r" sound, but you're not really pronouncing an "r".

Just say it like you do schön in danke schön. Easy enough, right? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

"I desired dragons with a profound desire"

"It struck me last night that you might write a fearfully good romantic drama, with as much of the 'supernatural' as you cared to introduce. Have you ever thought of it?" -Geoffrey B. Smith, letter to JRR Tolkien, 1915